Mistakes to Avoid when Growing a Wisteria

Wisteria is among the most spectacular vines in any home garden. But growing it can often be very challenging. If you're thinking about growing wisteria in your garden, consider the following obstacles.

Dry soil

Although wisteria is remarkably adaptable, it does best in a fertile, moist soil environment. When planted in a dry soil or soil that isn’t kept sufficiently moist, the vine can go into shock and die. Lack of watering is one of the most common mistakes gardeners make with wisteria.

Too Much Fertilizer

Another frequent mistake is to to overfeed the wisteria. Once the vine is established, wisteria doesn’t need much in the way of fertilizer. Instead, give the vine a shovelful of compost in early spring. This gives it sufficient nutrients for the season.

Insufficient Support

Wisteria is a climbing vine that requires sturdy support. Home gardeners frequently underestimate the weight of a mature wisteria and use supports that cannot sustain the plant. Over time, lack of proper support will cause the wisteria to collapse and grow over anything in its path. Remember, these vines can reach 25 feet in height.

Underpruning

When wisteria is neglected and not pruned sufficiently, the result is often a massive, woody tangle of vines. Gardening experts recommend pruning off a good 90 percent of new growth each year as a rule of thumb. This isn’t as outrageous as it sounds when you consider that a single runner can grow up to 12 feet in a year.

Overpruning

Home gardeners often see a sturdy wisteria that’s taken over and think there’s no such thing as overpruning. But when you remove too many of the flowering short laterals, which originate from the main trunk or stem, it will cause a shortage of blooms or a sparse-looking wisteria the following spring. The main idea is to remove or trim the long, wild runners and leave the short laterals to flower at will.

Unnecessary Removal

This often occurs when a wisteria has been seriously neglected for years, allowed to grow with abandon until it completely covers the side of a house, wall, porch or other structure. The runners get into eaves, heave foundations, crack concrete and generally cause a lot of damage. Avoid the temptation to completely remove the wisteria. That’s not only unnecessary, but it will rob the home garden of a wonderful plant specimen.

The solution is to do a thorough pruning job, cutting well below where you want the wisteria to re-grow. The new growth will occur the following spring. When rehabilitating an overgrown wisteria, remember that the plant will be only bloom for a few years, but will eventually flower again. Some major stems will partially or totally die. Cut off any dead parts as time goes on.

Tools And Timing

Two other mistakes common when growing wisteria are use of the wrong tools and underestimating how long wisteria takes to bloom. For pruning vines and water spouts, use long-reach pruners (not pole pruners). For trunks and woodier branches, use loppers, hand pruners and a pruning saw. Make sure all your tools are clean and sharp.

In terms of timing, expect to wait 5 to 6 years for Chinese wisteria to bloom, and 10 to 15 years for other varieties and cultivars.